package org.apache.samoa.instances;

/*
 * #%L
 * SAMOA
 * %%
 * Copyright (C) 2014 - 2015 Apache Software Foundation
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */

public class DenseInstanceData implements InstanceData {

  /**
   * Instantiates a new dense instance data.
   *
   * @param array
   *          the array
   */
  public DenseInstanceData(double[] array) {
    this.attributeValues = array;
  }

  /**
   * Instantiates a new dense instance data.
   *
   * @param length
   *          the length
   */
  public DenseInstanceData(int length) {
    this.attributeValues = new double[length];
  }

  /**
   * Instantiates a new dense instance data.
   */
  public DenseInstanceData() {
    this(0);
  }

  /** The attribute values. */
  protected double[] attributeValues;

  /**
   * Num attributes.
   *
   * @return the int
   */
  @Override
  public int numAttributes() {
    return this.attributeValues.length;
  }

  /**
   * Value.
   *
   * @param indexAttribute
   *          the index attribute
   * @return the double
   */
  @Override
  public double value(int indexAttribute) {
    if (this.attributeValues.length <= indexAttribute)
      return this.attributeValues[this.attributeValues.length - 1];

    return this.attributeValues[indexAttribute];
  }

  /**
   * Checks if is missing.
   *
   * @param indexAttribute
   *          the index attribute
   * @return true, if is missing
   */
  @Override
  public boolean isMissing(int indexAttribute) {
    return Double.isNaN(this.value(indexAttribute));
  }

  /**
   * Num values.
   *
   * @return the int
   */
  @Override
  public int numValues() {
    return numAttributes();
  }

  /**
   * Index.
   *
   * @param indexAttribute
   *          the index attribute
   * @return the int
   */
  @Override
  public int index(int indexAttribute) {
    return indexAttribute;
  }

  /**
   * Value sparse.
   *
   * @param indexAttribute
   *          the index attribute
   * @return the double
   */
  @Override
  public double valueSparse(int indexAttribute) {
    return value(indexAttribute);
  }

  /**
   * Checks if is missing sparse.
   *
   * @param indexAttribute
   *          the index attribute
   * @return true, if is missing sparse
   */
  @Override
  public boolean isMissingSparse(int indexAttribute) {
    return isMissing(indexAttribute);
  }

  /**
   * To double array.
   *
   * @return the double[]
   */
  @Override
  public double[] toDoubleArray() {
    return attributeValues;
  }

  /**
   * Sets the value.
   *
   * @param attributeIndex
   *          the attribute index
   * @param d
   *          the d
   */
  @Override
  public void setValue(int attributeIndex, double d) {
    this.attributeValues[attributeIndex] = d;
  }

  @Override
  public void deleteAttributeAt(int index) {

    double[] newValues = new double[attributeValues.length - 1];

    System.arraycopy(attributeValues, 0, newValues, 0, index);
    if (index < attributeValues.length - 1) {
      System.arraycopy(attributeValues, index + 1, newValues, index,
          attributeValues.length - (index + 1));
    }
    attributeValues = newValues;
  }

  @Override
  public void insertAttributeAt(int index) {
    if ((index < 0) || (index > numAttributes())) {
      throw new IllegalArgumentException("Can't insert attribute: index out "
          + "of range");
    }
    double[] newValues = new double[attributeValues.length + 1];

    System.arraycopy(attributeValues, 0, newValues, 0, index);
    newValues[index] = Double.NaN; //Missing Value
    System.arraycopy(attributeValues, index, newValues, index + 1,
        attributeValues.length - index);
    attributeValues = newValues;

  }

  @Override
  public InstanceData copy() {
    return new DenseInstanceData(this.attributeValues);
  }

}